ADSORPTION OF AEROSOL OT ON ALUMINA FROM MIXTURES OF WATER AND CYCLOHEXANE

The adsorption of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) on alum ina from mixtures of water and cyclohexane was studied. Although the a dsorption isotherms were Langmuir-type from water or cyclohexane alone , the adsorbed amount of AOT from the mixtures of water and cyclohexan e increased sharply at low AOT concentration, then showed a minimum, a nd then gradually increased again with increasing AOT concentration fo r all mixed systems. In addition, ESR spectra from methyl 12-doxylstea rate adsorbing on the alumina suggested that the order parameters incr eased with the addition of AOT, particularly at low AOT concentration for lower mixed ratios of water/cyclohexane systems. The adsorption me chanisms of AOT are also discussed. (C) 1998 Elsevier Science B.V.